1. Field of the Invention
The present invention relates to a laser treatment apparatus for treating an affected part by irradiating it with a laser beam for treatment.
2. Description of Related Art
In laser treatment apparatus which is represented by a YAG laser treatment apparatus used in the field of ophthalmology, the focal point of a laser beam for treatment is made to shift in an optical axis direction in relation to the focal point of an aiming light when an operation of incising posterior capsule for after cataract treatment or iris for glaucoma treatment is carried out, in order to reduce the effect by the impact of the treatment laser beam on an intraocular lens and to enhance the efficiency of incising. The YAG laser is constructed to concentrate the energy of the laser beam on the focal point, whereby cutting off the tissue irradiated with the laser beam.
FIG. 9 shows the case that the focal point of the treatment laser beam is shifted in the optical axis, in which the focal point of an aiming light is located at a position F1. In this case, there are two ways to shift the focal point of the YAG laser beam, namely, one way is to shift the focal point to a back side (an eye fundus side) as indicated by a position F2 and another is to shift the same to a front side (an operator side) as indicated by a position F3.
The former way to shift the focal point to the back side up to the position F2 is performed when an object which must not be injured by the YAG laser beam, such as an intraocular lens, exists on the front side. For treatment for the after cataract, it is necessary to incise opaque posterior capsule by the treatment YAG laser beam. In view of the intraocular lens that has been inserted on the operator side, however, the focal point of the YAG laser beam is shifted to the back side in order to prevent the laser beam from injuring the lens in error.
The latter way to shift the focal point to the front side up to the position F3 is performed when an object which must not be injured by the YAG laser beam exists on the back side.
In the above laser treatment, the setting of the focal shift point of the treatment laser beam is often changed according to patient eye cases and by each operator. It is to be noted that a focal shift point is generally determined by each individual operator with respect to the same disease case, and the setting thereof would not be largely changed.
However, in the case that the laser treatment apparatus is used for the treatment of a different patient""s eye (namely, an eye having a different disease) from the eye for which this apparatus was used last time, in particular, in the case that a single apparatus is shared between plural operators, some operators are apt to forget the confirmation or reset of the focal shift point of the laser beam and execute the laser irradiation using the focal shift point set at the last time use (e.g., at the use by another operator). Consequently, the intended treatment effect may not be obtained. In addition, when the treatment operation of the after cataract is performed using the focal point of the YAG laser beam remaining at the position corresponding to that of the aiming light or on the front side, there is the fear of erroneously injuring the intraocular lens.
The above apparatus is configured so that the setting of the focal shift point may be changed in step-by-step or in succession according to intended disease cases, operator""s choices, and others. Conducting the setting of the focal shift point every time is however troublesome for operators.
Irradiation conditions of a treatment laser beam such as an output value of and the number of irradiation pulses of the treatment laser beam are set prior to irradiation of the beam, though they are often changed according to intended disease cases, operator""s choices, and operating methods. As is the case with the focal shift point, if plural operators share the use of a single apparatus, some operators are apt to forget the confirmation or reset of the irradiation condition settings prior to execution of laser irradiation. Consequently, the intended treatment effect may not be obtained.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a laser treatment apparatus enabling settings of a desired focal shift point and laser irradiation conditions to easily obtain intended treatment effects.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the purpose of the invention, there is provided a laser treatment apparatus including: an aiming light optical system for delivering an aiming light to a predetermined affected part; laser irradiation means including a laser source for emitting a laser beam for treatment and an irradiation optical system for delivering the treatment laser beam emitted from the laser source to the affected part; focal shift means for shifting a focal point of the treatment laser beam from a focal point of the aiming light; position setting means for changeably setting an initial point of the focal point of the treatment laser beam to a desired point; command signal input means for inputting a command signal to change the focal point of the treatment laser beam to the initial point; and control means for controlling the focal shift means to change the focal point of the treatment laser beam to the set initial point in response to the input command signal, the control means being connected to the focal shift means, the position setting means, and the command signal input means respectively.
According to another aspect of the present invention, there is provided a laser treatment apparatus including: laser irradiation means comprising a laser source for emitting a laser beam for treatment and an irradiation optical system for delivering the treatment laser beam emitted from the laser source to an affected part of a patient; condition setting means for changeably setting an initial value of an irradiation condition to a desired value, the condition including at least one of an output value of the treatment laser beam and the number of emissions of the treatment laser beam; command signal input means for inputting a command signal for changing the irradiation condition of the treatment laser beam to the initial value; and control means for controlling the laser irradiation means to change the irradiation condition of the treatment laser beam to the set initial value in response to the command signal input by the command signal input means, the control means being connected to the laser irradiation means, the condition setting means, and the command signal input means respectively.